Concentration of trace inorganic species in surface snow along the route to Dome Fuji, Antarctica

In the southern hemisphere, especially Antarctica, it is considered that ocean and stratosphere are major sources of halogen species. However, there is little data about halogen species contained in snow and ice in Antarctica. In this research, trace inorganic species (Br, Cl, F, I) in Antarctica snow were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°01'S, 40°03'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The snow samples were also collected from a pit dug at Dome Fuji station. Those samples were collected in the 2009/2010 austral summer. The samples were transported to Japan without thawing. The quantitative analyses of elements were performed using an ion chromatograph mass spectrometer (IC-MS) and a quadrupole type inductively-coupled plasma mass spectrometer (ICP-MS). The IC-MS system consists of a single quadrupole type mass spectrometer (Agilent Technologies 6150) connected to an ion chromatograph (Dionex ICS-2000). 14 anion species including halogen species (Br^-, BrO₃^-, CH₃COO^-, CH₃SO₃^-, Cl^-, C₂O₄^2-, F^-, HCOO^-, I^-, IO₃^-, NO₂^-, NO₃^-, PO₄^3-, SO₄^2-) were analyzed by this system. The maximum concentration of Br^- and I^- was observed around 71°S and near 74°S on the traverse route. Average concentrations and maximum concentration of Br^- were 0.2 ng/ml and 0.4 ng/ml, respectively. Average concentrations and maximum concentration of I^- were 0.05 ng/ml and 0.3 ng/ml, respectively. Further results and discussion about the behavior and origin of halogen ion species in snow will be presented.